'''Gustav Adolf Deissmann''' (7 November 1866 – 5 April 1937) was a German Protestant theologian, best known for his leading work on the Greek language
used in the New Testament
, which he showed was the ''koine
'', or commonly used tongue of the Hellenistic
world of that time.
[A. Gerber, 'Gustav Adolf Deissmann (1866-1937): trailblazer in biblical studies, in the archaeology of Ephesus, and in international reconciliation’, ''Buried History, Journal of the Australian Institute of Archaeology'', 41, 2005, pp. 2-3.]